SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9101f7169d8ecf783acd4532d7525072fce07df87bce5628b648510ee4b57b96' 
  AND token = 'v4jqfX4QK1guWA+vuDy5ZTiAYH7YBbBP7HoNtT785V8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}